Errors encountered while running Web Dypro Java after defining in VA

hi all,

after connecting my MS SQL database to the Visual Admin i encountered this error while running my web dynpro project:

com.sap.engine.services.dbpool.exceptions.BaseSQLException: ResourceException in method ConnectionFactoryImpl.getConnection(): com.sap.engine.services.dbpool.exceptions.BaseResourceException: SQLException thrown by the physical connection: java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.

May i know what is causing this problem and is there a clear step by step instruction for me to solve it? thx